Pressure terminals for electrical connectors



Nov. 7, 1961 G. H. FEUSTEL ETAL 3,008,117

PRESSURE TERMINALS FOR ELECTRICAL CONNECTORS Filed Oct. 51, 1957 ZZZ United States Patent 3,008,117 PRESSURE TERMINALS FOR ELECTRICAL CONNECTORS George H. Feustel, Chicago, and Jack R. Tinsman, Park Ridge, 111., assignors to The Pyle-National Company,

Chicago, III., a corporation of New Jersey Filed Oct. 31, 1957, Ser. No. 693,699 12 Claims. (Cl. 339-95) This invention relates generally to electrical connectors and more particularly to a pressure terminal for an electrical connector wherein inner and outer terminal parts are locked against axial separation by ring members carried on the outer part and having tangs for engaging and penetrating the inner part.

It is an object of the present invention to provide a terminal connector which will withstand substantial axial pullout forces and which will make positive electrical contact and have a minimum of electrical resistance through the connection.

A further object of the present invention is to provide a terminal connector which will withstand considerable vibration and shock and which will minimize temperature rise through the joint.

Yet another object of the present invention is to provide a terminal connector which is simple and eco nomical to manufacture and which will be simple and foolproof in operation and use.

A further object of the present invention is to provide a terminal connector which can be connected without the use of tools, or without necessitating the use of heat or of solder and other complicated assembling procedures.

Yet another object of the present invention is to provide a terminal connector which will work properly with either solid or stranded conductors.

A still further object of the present invention is to provide a terminal having improved corrosion resistance and minimum temperature rise even after subjection to corrosive conditions.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheet of drawings in which a preferred structural embodiment of an electrical terminal incorporating the principles of the present invention is shown by way of illustrative example.

On the drawings:

FIGURE 1 is an elevational view of the electrical terminal incorporating the principles of the present invention;

FIGURE 2 is a cross-sectional view taken substantially on line IIII of FIGURE 1 and showing the parts positioned as during the course of assembly;

FIGURE 3 is a view similar to FIGURE 2, but showing the parts locked together in assembly;

FIGURE 4 is a cross-sectional view taken substantially on line IV--IV of FIGURE 3; and

FIGURE 5 is an elevational view of one of the ring members provided in accordance with the principles of the present invention.

As shown on the drawings:

The electrical terminal of the present invention is indicated generally at and comprises an inner part 11 and an outer 12, as well as a plurality of locking par-ts or ring members each indicated at 13.

The inner and outer parts 11 and 12 constitute electrical connector contacts such as are employed as terminals mounted on boards or in other environments requiring a mechanical fastener for an electrical terminal. Thus, it will be appreciated that although the inner part ice 11 is illustrated herein as a stranded conductor having a sheath of insulating material 14, the inner part 11 could also constitute a solid conductor of well known type.

In like maner, the specific construction of the outer part 12 can also be varied. There is illustrated herein a connector part having a body portion 16 with a sleeve forming a generally tubular projection 17 and particularly characterized by an internal recess or bore 18 open at one end as at 19 and terminating at its other end as at 20.

The walls of the sleeve 17 extend circumferentially and as shown in FIGURE 4 include an outer peripheral surface 21, as well as an inner peripheral wall 22.

The outer peripheral surface 21 of the projection 17 is particularly characterized by the formation therein of a plurality of axially spaced, circumferentially extending recesses or grooves 23.

Each groove 23 has a first radially extending wall 24 and a second radially extending wall 26. The walls 24 and 26 are joined by a bottom wall 27.

The bottom walls 27 of the grooves 23 are each tapered in axial direction, thereby to provide both axial and radial components, and it will be noted that all of the walls 27 are tapered in the same axial direction.

The projection 17 is further characterized by the provision of one or more axially extending radial slots 28. In the particular embodiment illustrated, there is provided two circumferentially spaced, axially extending radial slots 28, the slots 28 being formed to extend through the projection between the inner and outer peripheral walls 21 and 22, and in the area of the grooves 23 between the end opening 19 and the wall 20.

Confined for limited axial and radial movement within each groove 23 is one of the locking parts or ring members 13. Referring to the drawings, it will be noted that each locking part 13 constitutes a generally annular flat disk-like member having an inner peripheral surface 29 and an outer peripheral surface 30, and including axially spaced faces shown at 31 and 32. Each ring member 13 is radially split as at 33 and is further characterized by the provision of one or more radially inwardly extending tangs or tongues or lugs shown at 34, and preferably corresponding in number to the slots 28 formed in the projection 17.

The rings 13 are assembled and carried on the projection 17 with the corresponding tangs 34 extending through the slots 28 and into the bore or recess 18.

The radial innermost portions of the tanks 34 are offset in longitudinal direction, thereby to provide a first face or surface 36 on one side of each tang 34, and a second face 37 on the opposite side thereof. The faces 36 and 37 preferably converge by virtue of the tangs being tapered or sharpened to a point or edge, as indicated at 38.

In operation, the inner and outer parts are assembled by applying axial forces to the parts along a common axis, thereby to effect relative axial assembly movement in one direction, as shown in FIGURES 1 and 2. When such assembly occurs, the tangs 34 engage against the outer peripheral surface of the inner part 11 and a portion of the axial force is converted into an outwardly directed radial force tending to move the locking parts 13 radially outwardly. Moreover, the axial force applied to each of the locking parts 13 will force the locking parts in a generally axial direction with the inner peripheral surface 29 engaging against the adjoining bottom wall 27 of each corresponding groove 23. When the locking parts 13 ride up on the inclined walls 27, it will be app-eciated that the tangs 34 tend to move radially outwardly. Thus, insertion of the inner part 11 into the outerpart 12 is facilitated. It will be noted that the tangs 34 extend through the corresponding slots 28 a sufficient radial distance to engage against the peripheral surface of the inner part 11.

After the inner member 11 is fully inserted within the recess 18, any application of force tending to effect withdrawal or separation of the parts in an opposite direction will result in the edge or point 38 penetrating the surface of the inner member 11 and the face 37 will tend to bite into the inner member 11.

The axial separation force will then move the ring parts or ring members 13 towards the position of FIG- URE 3 until the respective faces 32 engage against the side walls or shoulders 26 of the respective grooves 23. As the ring parts 13 movedownwardly in the g ooves 23 and inwardly on the inclined surfaces 27, the tangs 34 are permitted to bite deeper into the inner part 11, thereby firmly resisting withdrawal or axial separation. As a result, the inner and outer parts 11 and 12 are firmly locked together in good electrical contact with one another, and an efficient joint both electrically and mechanically is produced. It will be understood that the split 33 accommodates any expansion required of the ring members 13.

Although various minor modifications might be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.

We claim as our invention:

1. An electrical terminal comprising an outer electrical connector contact having a circumferentially extending axially slotted wall, a circumferentially extending peripheral recess in said wall having axially spaced radially extending side walls and an axially tapered bottom wall extending therebetween, a split ring in said recess and having a tongue extending radially inwardly through said slotted wall, said split ring having an inner peripheral portion engaging said bottom wall and slidably movable thereon, and an inner conductor inserted into said outer contact and having a diameter sufficient to afford pressure engagement by said tongue, said inner peripheral portion of said split ring being moved towards one of said side walls upon insertion of said inner conductor to facilitate insertion of said inner conductor upon corresponding radial outward movement of said tongue, and said split ring moving towards and against the opposite side wall of said recess upon corresponding radial inward movement of said tongue to prevent separation of the inner conductor and outer contact after assembly.

2. An electrical terminal comprising inner and outer conductor and connector parts, said outer connector parts having a plurality of axially spaced circumferentially extending grooves formed therein and having further formed therein an axial slot, 9. locking ring in each groove and each having a tongue in said slot for engaging said conductor part, said outer connector part having means formed at the bottom of each groove moving said locking ring radially outwardly upon axial assembly of the inner and outer parts, said tongue being forced inwardly into locking engagement with the inner part in response to an axial separating force between said inner and outer parts, said grooves having bottom Walls tapered to have radial and longitudinal extent, whereby to move the tongues radially outwardly upon limited axial movement of the ring in a corresponding groove.

3. An electrical terminal as defined in claim 2, said tongues having the radially innermost terminal portions thereof sharpened to facilitate penetration of said inner member.

4. An electrical terminal as defined in claim 3, said innermost portions thereof of said tongues being offset in a longitudinal direction such as to improve the locking action and penetration of said tongues when the inner conductor is moved slightly outwardly relative to said outer contact.

5. A terminal comprising axially separable inner and outer parts provided by a conductor and an electrical connector contact, respectively, a radially movable locking part carried by said outer part and having portions projecting generally radially inwardly and with a longitudinal offset portion dimensioned for operative engagement with said inner part, and axially tapered wedging means on said outer part guiding said locking part for limited radial movement outwardly upon initial relative movement of said inner and outer parts in one direction and for radial movement inwardly to resist relative movement of said inner and outer parts thereafter in an opposite direction, whereby said projecting portions of said locking part are forced into engagement with the inner part.

6. An electrical terminal com-prising inner and outer telescoping parts provided by a conductor and an electrical connector axially assembled upon relative axial movement in one direction, a locking ring carried by said connector and having portions dimensioned to be biased into contact with said conductor, means on said connector guiding said locking ring and including camming surfaces having sufficient radial extent to effect limited radial movement between said locking ring and said connector, said locking ring having axially offset tangs biting into said conductor when said ring is moved radially inwardly in response to separation forces tending to separate the parts, said tangs being forced into engagement with the conductor.

7. An electrical terminal comprising a tubular outer electrical connector contact member and an inner conductor member inserted therein, said outer member having a longitudinally extending slot formed in the walls thereof, a resilient ring member carried by said outer member and having a lug extending radially inwardly through said slot, the innermost end of said lug being offset and being spaced inwardly sufficient to engage said conductor member upon assembly to move said lug outwardly, said outer member having a wall tapered to have radial and longitudinal extent and forming axial wedge means forcing said lug radially outwardly when said inner and outer members are engaged, said lug being forced inwardly into locking engagement with said conductor member whenever said inner and outer members tend to move in disengaging direction.

8. An electrical terminal comprising an outer electrical connector contact part having a circumferentially extending axially slotted wall, said wall having a circumferentially extending peripheral recess, a split ring in said recess and having a tongue extending radially inwardly through said slotted wall, and an inner conductor part inserted into said outer contact part and being of sufficient size to engage said tongue, said split ring and said outer part having camrning means including a tapered wall in the bottom of said recess moving said split ring radially outwardly and axially inwardly during insertion of said inner conductor part past said tongue but accommodating movement of said split ring radially inwardly and axially outwardly whenever said inner and outer parts tend to move in a separating direction so that said tongue will engage and retain said inner and outer parts in locked together assembly.

9. An electrical connector comprising inner and outer connector parts assembled by applying axial forces to the parts along a common axis, a locking part comprising a split resilient ring on said outer part and having a tang extending inwardly toward said inner part, and cam ming means guiding said split resilient ring to move said tang axially inwardly and radially outwardly during insertion of said inner part into said outer part, but accommodating movement of said split resilient ring radially inwardly and axially outwardly for penetration of said tang into said inner part to resist withdrawal of said inner part by axial separation from said outer part.

10. A conductor terminal comprising inner and outer telesc ping terminal parts and a radially movable locking ring encircling the parts, said outer part having an axially slotted wall, said locking ring having an inwardly projecting portion engaging said inner part and extending through the axially slotted wall of said outer part, and a wall on said outer part tapered to have radial and longitudinal extent to form axially tapered means between said outer part and said locking ring and forcing said inwardly projecting portion radially outwardly while said terminal parts are being telescopically assembled but accommodating said projecting portion of said locking ring being forced radially inwardly into engagement with said inner part to prevent separation of the parts Whenever axial separation forces are applied to the parts.

11. An electrical connector as defined in claim 9, said camming means including the innermost portion of said 15 2,694,188

References Cited in the file of this patent UNITED STATES PATENTS 1,665,424 Strahm Apr. 10, 1928 2,160,353 Conners May 30, 1939 2,221,651 Pelz Nov. 12, 1940 2,499,709 Whitman et al. Mar. 7, 1950 Poupitch Nov. 9, 1954 

